Method for producing hot-rolled steel sheet without edge cracks and method for producing cold-rolled steel sheet without edge cracks

摘要

Disclosed are: a hot-rolled steel sheet; a cold-rolled steel sheet which has a thickness of 0.2 mm or less and does not undergo edge cracking; and process for producing the steel sheets. The hot-rolled steel sheet comprises, in mass%, 0.001 to 0.10% of C, 0.005 to 0.80% of Si, 0.01 to 2.0% of Mn, 0.001 to 0.40% of P, 0.10% or less of S, 0.001 to 0.10% of Al and 0.020% or less of N, with the remainder being Fe and unavoidable impurities, wherein the main phase structure comprises ferrite, the ferrite has an average crystal particle diameter of 10 to 25 µm, and each of the crystal particles of the ferrite has an aspect ratio (Nx/Ny) of 0.70 to 1.00. The cold-rolled steel sheet is produced by the cold-rolling of the hot-rolled steel sheet and has a thickness of 0.2 mm or less.